Nuclear Energy Futures CDT Research Themes

Applications are invited from candidates who have an interest in PhD projects in any of the themes detailed below.

The list of projects available is not exhaustive, although the projects listed have preference: they have funding agreed and are available immediately.

Applicants who cannot find a suitable project listed should discuss their preference with the CDT admissions panel; although we will do our best, there is no guarantee we can find an appropriate supervisor or funding. Specific research topics will be agreed with candidates when an offer is made.

Research Projects

Title: Advanced shielding materials for next-generation nuclear fusion power reactors‌Description: Our communal goal of clean and sustainable energy could be met by progress in nuclear fusion technology. Depending on this is the development of improved fusion reactor shielding materials.We work particularly on understanding the degradation mechanisms of these materials in extreme fusion reactor environments, including severe thermal and mechanical stresses, corrosion and irradiation. The ultimate goal of our work is to inform fusion reactor design and allow the development of materials with enhanced damage-tolerance.Institution: Imperial College LondonSupervisor(s): Dr Sam Humphry-Baker (ICL)Sponsor(s): EPSRC and Tokamak Energy Ltd

Title: Analysis and interpretation of creep-fatigue crack growth behaviour‌Description: Life extension of the UK’s advanced gas cooled reactors (AGRs) is dependent on the assurance of the safety of their structural components. As many AGR components operate in the creep range, it is important to understand and to be able to predict creep and creep-fatigue crack growth for real or postulated defects in these components.The main aim of this work is to develop improved methods for interpreting crack growth data in creep-fatigue tests for situations where cracking is discontinuous. This will be achieved by using a combination of novel experimental techniques and study methods.Institution: Imperial College LondonSupervisor(s): Dr Catrin Davies (ICL), Dr Joe Corcoran (ICL), Prof Karam Nikbin (ICL), Prof David Dean (EdF Energy) and Dr Daniel Hughes (EdF Energy)Sponsor(s): EPSRC and EdF Energy

Title: Application of machine learning to the development of nuclear thermal hydraulicsDescription: The study of thermal hydraulics in a nuclear reactor, in both primary and secondary circuits is vital in the assessment of the performance and safety of any reactor design. The flow of coolant is a challenging problem in which coolant flows through a complex arrangement of channels, ducts, valves and other components and is subject to wall heat transfer where a wide range of boiling regimes could occur, particularly in accident scenarios. The objective of this project is to investigate more rigorous and reliable means by which reduced order models (ROMs) may be obtained that combine the efficiency of System Codes with the accuracy of Computational Fluid Dynamics. The approach here is to use recent developments in machine learning and artificial intelligence.Institution: Imperial CollegeSupervisor(s): Dr Mike Bluck (ICL)Funding: EPSRC and Imperial College London

Title: Characterising creep crack growth behaviour in austenitic steel weldments Description: Nuclear Power Plant components operate at high temperatures where failures by creep mechanisms are possible. Some components can contain crack-like defects which could grow by creep and fatigue processes. The main aim of this work is to develop an improved understanding of creep crack growth behaviour in C(T) specimens extracted from as-welded austenitic steel weldments, with particular emphasis on developing an improved understanding of the crack driving force resulting from the combination of residual stress and applied loads.Institution: Imperial CollegeSupervisor(s): Dr Catrin Davies (ICL), Prof Karam Nikbin (ICL), Prof David Dean (EdF Energy) and Dr Daniel Hughes (EdF Energy)Sponsor(s): EPSRC and EdF Energy

Title: Constraint effects on creep crack growth behaviour in 316H stainless steel‌Description: Life extension of the UK’s advanced gas cooled reactors (AGRs) is dependent on the assurance of the safety of their structural components. As many AGR components operate in the creep range, it is important to understand and to be able to predict creep and creep-fatigue crack growth for real or postulated defects in these components. The main aim of this work is to investigate the effects of constraint (in-plane and out-of-plane) on creep crack growth in 316H steel at 550°C, with particular emphasis on developing an improved understanding of crack growth behaviour in thin section components.Institution: Imperial CollegeSupervisor(s): Dr Catrin Davies (ICL), Prof Karam Nikbin (ICL), Prof David Dean (EdF Energy) and Dr Daniel Hughes (EdF Energy)Sponsor(s): EPSRC and EdF Energy

Title: Environmental effects on creep crack growth behaviour‌Description: Life extension of the UK’s advanced gas cooled reactors (AGRs) is dependent on the assurance of the safety of their structural components. As many AGR components operate in the creep range, it is important to understand and to be able to predict creep and creep-fatigue crack growth for real or postulated defects in these components. The aim of this project is to investigate the creep crack growth behaviour of Type 316H steel in both a pressurised simulated AGR CO2 environment and an inert environment or vacuum to discover the significance of any environmental contributions to creep crack growth in both a laboratory air environment and a pressurised simulated AGR CO2 environment.Institution: Imperial CollegeSupervisor(s): Dr Catrin Davies (ICL), Prof Karam Nikbin (ICL), Prof David Dean (EdF Energy) and Dr Daniel Hughes (EdF Energy)Sponsor(s): EPSRC and EdF Energy

Title:Influence of microstructure on the diffusivity of hydrogen in advanced steelsDescription: Significant accumulation of hydrogen in metallic systems is known to promote premature failure and is a primary concern in current and future nuclear reactors. In advanced steels, this happens due to their complicated microstructure, their very high strength, and the low solubility of H in steel. This project is aimed at conducting fundamental studies to understand and predict the influence of the microstructure on the mobility of H in multi-phase steels.Institution: University of CambridgeSupervisor(s): Dr Enrique Galindo-Nava (Cambs)Sponsor(s): EPSRC and Rolls-Royce Plc

Title: Influence of stress and strain on hydride matrix interactions in Zr alloysDescription: Zirconium cladding is often used in water reactor cores due to favourable properties. Cladding is used for a long period of time to hold the fuel and gradually it can react with water to produce a thin zirconium oxide scale and results in an ingress of hydrogen ions into the material. At elevated temperatures this hydrogen is in solution and does not significantly affect performance. However, in some cases, such as a shut down, the hydrogen can come out of solution and form a second phase (zirconium hydrides). In this project we will study the impact of hydride formation on mechanical properties and opportunities to influence this mechanism through improved cladding design and microstructure control.Institution: Imperial CollegeSupervisor(s): Dr Ben Britton (ICL) and Rob Bentley (Rolls-Royce)Sponsor(s): EPSRC and Rolls-Royce Plc

Title: Modelling of SiC/SiC composites for accident tolerant nuclear fuel‌Description: Silicon carbide composites (silicon carbide matrix with silicon carbide fibres) are proposed as a next generation cladding material because they avoid the problem of in-service hydrogen pickup and, under accident conditions, the highly exothermic reaction created between steam and zirconium alloys. However, manufacturing the composite in an efficient manner to produce cost effective fuel cladding needs significant research. The aim is to develop a microscale material model to study a variety of interfacial fibre/matrix strengths and fibre weaves orientations to discover the best combinations for manufacture and testing. Institution: Imperial CollegeSupervisor(s): Dr Mark Wenman (ICL), Glyn Rossiter (NNL), Daniel Shepherd (NNL) and David Goddard (NNL)Sponsor(s): EPSRC and National Nuclear Laboratory